Whether you are resolving to hit the gym more in the new year or not, deciding to care for your health is always a life-changing decision.  But how much time spent on improving your physical health is enough? And how much time is too much?

It is likely that you have heard federal guidelines, which say that you need 30 minutes of moderate-intensity exercise, five days a week. However, if you're looking for certain health benefits, the time you spend could actually be more than 30 minutes...or less. 

Here's what the numbers look like, according to your current habits or desired outcomes.

If you hope to lower your blood pressure.

Love spending a long-time exercising? Research published in the American Journal of Hypertension found that 61 to 90 minutes of exercise a week was actually more effective at lowering systolic blood pressure than 30 to 60 minutes a week. 

If you need a better attention span.

Walks in nature are so restorative that they can even help you if you lack an ability to focus. One study revealed that of the participants who took a walk through the city, in nature, or did not walk at all, the nature group scored the best on proofreading task. Plus, children with ADHD have been found to concentrate better after a mere 20 minutes of being in a park.

If you want a better memory.

The Harvard Health Blog published research suggests 120 minutes of moderate-intensity aerobic exercise per week in order to increase the size of the hippocampus. This section of the brain is responsible for your learning, as well as verbal memory.

If you're always at work.

You may have heard about the terrible health effects of sitting for a prolonged period of time. Today, the average worker in the office sits for about 10 hours -- hours spent in front of a screen, going through emails, making calls -- only to go home and sit more, online or in front of the TV.

According to the British Journal of Sports Medicine, Americans should begin to stand, move and take breaks for at least two out of eight hours at work, and work your way toward four. 

If you're looking for improved mental health.

Beyond day-to-day stress, a certain amount of exercise can be key for relieving symptoms of depression. For example, according to the Harvard Special Health Report, if you walk briskly for 35 minutes a day, 5 times a week, mild to moderate depression can be significantly improved. 

When you spend time on your physical health, you are gaining not only a longer life, but a more enjoyable, higher quality of life as well. What are you waiting for? Go reap the benefits of a healthy lifestyle.